Campylomma marinum Yasunaga & Ito, sp. nov.

Figs. 1A–B, 2A–B, 3A–B, 4A–B, 5A–B, 6A–H, 7A–F

Material examined. Holotype (♂). JAPAN: Kyushu, Oita Pref., Otsuka (seashore with halophilic herbs, Fig. 1A–B), 33°36’49”N 131°12’31”E, Suaeda maritima, 24 Aug 2024, R. Ito (NWHS) (AMNH _ PBI 00378807) . Paratypes: JAPAN: Kyushu, same data as for holotype, except for date, 26 Aug 2023, 3♂, 1♀ (TYCN) ; 26 Oct 2023, 2♂, 2♀ (TYCN); 24 Aug 2024, 2♂, 4♀ (TYCN); 28 Sep 2024, 1♀ (TYCN) .

Diagnosis. Recognized by its comparatively small size; uniformly pale green basic coloration (Fig. 2A–B); reduced (sometimes obliterated) dark spots on ventral metafemur (Figs. 1B, 2A–B); smooth pygophore lacking thumb-like process; minutely spinulate blade with rather long spicule on apical part of vesica (Figs. 4B, 6C–D); and rather wide female genital chamber with elongate oval, narrow-rimmed sclerotized rings (Fig. 4A), in addition to its unique host plant association with a halophyte, Suaeda maritima .

Based on the similar shape of the genitalia and same host plant, this new species is evidently sister to Campylomma salaciella Yasunaga & Duwal (Fig. 1C–D), from which C. marinum sp. nov. can be distinguished by the following characters: smaller size and shorter appendages (e.g. antennomere II, metafemur and metatibia as in Table 1); smaller dark spots on ventral metafemur (Fig. 2B vs. 2D); narrower peritreme of scent efferent system (Fig. 6E vs. 6J); more sharply tapered phallotheca (Figs. 4A, 7B vs. 4C, 7H); longer and slenderer apical spicule on vesica (Fig. 4B vs. 4D); elongate oval sclerotized rings (Fig. 5A vs. 5C); and larger scaly microstructures on narrower interramal sclerite (Fig. 7F vs. 7L). Each sibling species is currently considered to be allopatric in the temperate seashore of NE. Kyushu, Japan (Fig. 1A–B) and tropical coast along the Gulf of Siam (Fig. 1C–D).

In Japan (Kyushu area), the other congener, C. tanakakianum Yasunaga, Duwal & Schuh, is also externally most similar to C. marinum sp. nov. However, the former can be distinguished from the present new species by the uniformly darkened antennomere I, antennomere II almost equal in length to head width across eyes, and sharpened apical part of vesica with shorter spicule (Fig.7O). Two available specimens (holotype male and paratype female) of C. tanakakianum were collected by a UV light trap near the seashore on Kabashima Island, Nagasaki City [32º33'15"N 129º46'30"E] (Yasunaga et al. 2015), where the halophyte, Suaeda maritima, is not present.

Description. Male: Body pale or yellowish green (often fading to pale brown in dry-preserved specimens), elongate oval, relatively small in size; dorsal surface shining, with uniformly distributed, pale, simple, semierect setae mixed with flat, lanceolate setae (Fig. 6C). Head tinged with olive in fresh specimens (Fig. 2A). Antenna pale brown; antennomere II shorter than combined length of III+IV. Labium pale reddish brown, relatively long, reaching but not exceeding apex of metacoxa; apical 2/3 of segment IV darkened. Thoracic pleura pale green (Fig. 2B), sometimes partly darkened in dry-preserved specimens (Fig. 3A); metathoracic scent efferent system with narrow, rounded peritreme (Fig 6E). Hemelytra shining; membrane pale grayish brown, semi-transparent. All coxae and legs pale brown (pale green in live individual); ventral dark spots of each femur small, reduced (sometimes obliterated); row of minute spicules on anterior margin of metafemur present at apical half (Fig. 6F); meta-tarsomere II slightly shorter than III (Fig. 6H); pretarsal structure as in Fig. 6G, rather small pulvilli. Abdomen shiny pale green; genital segment sometimes darkened in dry-preserved specimens (Fig. 3A). Male genitalia (Figs. 4A–B, 7A–D): pygophore (genital segment) smooth, lacking thumb-like process; phallotheca sharply tapered apically (Figs. 4A, 7B); vesica sigmoid, with an apical, spinulate blade and relatively long, slender spicule (Figs. 4B, 7C–D). Female: General coloration and basic shape as in male, but body wider and more ovoid, and antennal segment II slenderer. Female genitalia (Figs. 5A–B, 7E–F): Genital chamber rather wide, with elongate oval, narrow-rimmed sclerotized rings (Fig. 5A); posterior wall of bursa copulatrix densely spinulate along anterior margin (Fig. 7E); interramal sclerite narrow, with densely distributed, relatively large scaly microstructures (Fig. 7F).

Measurements: See Table 1.

Etymology. From Latin adjective marinum (= of the sea), referring to the habitat of this new species restricted to the seashore plant communities.

Distribution. Japan (Kyushu: Oita Prefecture).

Biology. This monophagous new species is associated only with a halophilic goosefoot, Suaeda maritima, on which both adults and immature forms were found. A bivoltine life cycle is assumed for Campylomma marinum sp. nov. as the teneral adults and late instar immature forms were captured in mid-August and late September.

The halophilic plant community in the type locality is dominated by Artemisia fukudo Makino ( Asteraceae) (Fig. 1A), with which a greater number of the common, polyphagous congener, Campylomma lividum are associated. Since Suaeda maritima sparsely mixed at the site (Fig. 1B), only a few specimens of the present new species were collected along with many individuals of C. lividum . For this reason, the presence of C. marinum sp. nov. appears to have previously been unrecognized.